Engineering highly dispersed AgI nanoparticles on hierarchical InS hollow nanotube to construct Z-scheme heterojunction for efficient photodegradation of insecticide imidacloprid.

Increasing the exposure of active sites and improving the intrinsic activity are necessary considerations for designing a highly efficient photocatalyst. Herein, an InS/AgI stable Z-scheme heterojunction with highly dispersed AgI nanoparticles (NPs) is synthesized by the mild self-templated and in-situ ion exchange strategy. Impressively, the optimized InS/AgI-300 Z-scheme heterojunction exhibits superior photodegradation activity (0.020 min) for the decomposition of insecticide imidacloprid (IMD), which is extremely higher than that of pure InS (0.002 min) and AgI (0.013 min). Importantly, the three-dimensional excitation-emission matrix (3D EEMs) fluorescence spectra, high-resolution mass spectrometry (HRMS), the photoelectrochemical tests, radical trapping experiment, and electron spin resonance (ESR) technique are performed to clarify the possible degradation pathway and mechanism of IMD by the InS/AgI-300 composite. The enhanced photocatalytic performance is attributed to the highly dispersed AgI NPs on hierarchical InS hollow nanotube and the construction of InS/AgI Z-scheme heterojunction, which can not only increase active site exposure, but also improve its intrinsic activity, facilitating rapid charge transfer rate and excellent electron-hole pairs separation efficiency. Meanwhile, the practical application potential of the InS/AgI-300 composite is systematically investigated. This study opens a new insight for designing catalysts with high photocatalytic performance through a convenient approach.